If core electrons completely shielded valence electrons from
nuc...

Question

If core electrons completely shielded valence electrons from 
nuclear charge (i.e., if each core electron reduced nuclear charge 
by 1 unit) and if valence electrons did not shield one another 
from nuclear charge at all, what would be the effective nuclear 
charge experienced by the valence electrons of each atom? 
b. Ca

Accepted Answer

hey everyone in this example, we need to calculate effective nuclear charge of valence electrons of magnesium. Based on the below theoretical conditions. We want to initially recall our formula for effective nuclear charge represented by the symbol ZF and that is equal to our atomic number of our atom. Z subtracted from our core electrons of our atom. So our next step is to focus on the aspects of magnesium First beginning with the atomic number. So when we find magnesium on our periodic tables, we see that it has an atomic number Z corresponding to 12. We would then go ahead and notice that magnesium was located in group To a on the periodic table. And we should recall that the group number will correspond to the number of valence electrons. And so because we're in group two a. We have two valence electrons with magnesium. Our next step is to calculate the magnesium core electrons. And so we would do so by taking our atomic number and subtracting that from our valence electrons. and so what we would have is our atomic number 12 for magnesium minus the two valence electrons in the outer shell of magnesium. And so that would that would Results in our core electrons equaling 10 core electrons for Magnesium. And now we're ready to calculate our effective nuclear charge for magnesium Which is going to equal our atomic number again for magnesium 12 - Our core electrons and magnesium, which we found above to be 10. And so this is going to equal a value of plus two. And so we would say that therefore the effective nuclear charge of magnesium is equal to plus two corresponding to choice B. And so this would be our final answer to complete this example. If you have any questions, please leave them down below, and I will see everyone in the next practice video.

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